Objective      To study porcine peroxisome proliferator activated receptor gamma (PPAR-γ) expression changes after carotid arte

ry stent implantation and its influence on the vascular smooth muscle phenotype.       Methods      Twelve miniature pigs were randomly divided into 3 groups

normal control group (control group

n=4)

stent implantation group (stent group

n=4)

and stent implantation combined with rosiglitazone (ROSI) treatment group (ROSI group

n=4). Angiography was used to observe vascular morphology. Immunohistochemical assay was used to observe the vascular pathological morphology and PPAR-γ expression. Western blotting was used to test the expression changes of PPAR-γ and smooth muscle 22 alpha (SM22α) in blood vessels with stents and analyze their relationship with vascular smooth muscle phenotype transformation of vascular remodeling.       Results      Angiography showed that the extent of vessel stenosis in the stent group was higher than that in the ROSI group after 3 months (1.46 mm±0.14 mm vs  0.91 mm±0.13 mm

P

0.05). The results of HE staining found that in stent group

the intimal proliferation of smooth muscle was higher than that in ROSI group. Immunohistochemical assay results showed the expression score of PPAR-γ in the stent group was lower than those in the control group and ROSI group (0.90±0.22 vs 5.85±0.29 vs  5.04±0.46

P

0.05)

while the ROSI group and control group had no significant difference (

P

0.05). Western blot results showed that the expression of PPAR-γ/SM22α of the stent group was lower than that of the control group [(3.12±1.42)%/(16.72±5.34)% vs  (19.87±5.33)%/(68.85±9.73)%

P

0.05

]

. Phenotype of vascular smooth muscle of the stent group transformed from contractile type to synthetic type. Expression of PPAR-γ/SM22α in the ROSI group [(23.17±4.23)%/(58.63±12.81)%

]

was higher than that of the stent group (

P

0.05). Phenotype of vascular smooth muscle of the ROSI group transformed from synthetic type to contractile type. No significant difference was observed in PPAR-γ/SM22α expression between the ROSI group and the control group.       Conclusion      PPAR-γ par

ticipates in the process of vascular smooth muscle phenotype conversion after stent implantation

and thus may be one potential target for the treatment of restenosis after stent implantation.